I have a problem with a mixed GLM I run, for the second time, on SPSS 24, after running it with the previous version I had (SPSS 22).

All the results are exactly the same (descriptives, within subjects effects, interactions), but not the between-subjects effect. In this case, it goes from F(1,162) = 10.125, p = .002, η2 = .059 (version 22) to F(1,162) = .000, p = 1.000, η2 = .000 (version 24). I have both the outputs here in front of me.
I have no idea what is happening. Any ideas?